I think this is a more simple method
just take x2 as 2*x2 and from there on arrange the expressions a bit then you will get the answer as follows
1/2log|(1+x)/(1-x)-1/2tan^-1x
5 Answers
\hspace{-16}$I Dont have much Idea about that type of Integral....\\\\\\ May be it is an Elleptical Integral of $\bf{(I)}$ or $\bf{(II)}$ Type..\\\\\\Given $\bf{\int\frac{x^2}{\sqrt{1-x^4}}\;dx = \int x^2\cdot \left(1-x^4\right)^{-\frac{1}{2}}dx}$\\\\\\ Now Using Chebyshev integral....\\\\\\ $\bf{\bullet \;\; \int x^m\cdot (a+bx^n)^{p}\; dx}$\\\\\\ Where $\bf{m,n,p}$ are Rational no. and the given Integral\\\\\\ is Integral in elementry form only if ............\\\\\\ $\bf{\left(\frac{m+1}{n}\right)\in \mathbb{Z}}$ \bf{\underline{\underline{or}}} $\bf{\left(\frac{m+1}{n}+p\right)\in \mathbb{Z}}$\\\\\\ Now in $\bf{\int x^2\cdot \left(1-x^4\right)^{-\frac{1}{2}}dx}$\\\\\\ Here $\bf{m=2\;\;,a=1\;\;,b=-1\;\;,n=4\;\;,p=-\frac{1}{2}}$\\\\\\
\hspace{-20}$So $\bf{\left(\frac{2+1}{4}\right)\neq \mathbb{Z}}$ \bf{\underline{\underline{or}}} $\bf{\left\{\left(\frac{2+1}{4}-\frac{1}{2}\right)\right\}\neq \mathbb{Z}}$\\\\\\ So we can Not Integrate $\bf{\int\frac{x^2}{\sqrt{1-x^4}}\;dx}$ in terms of\\\\\\ elementry function..
Aditya Agrawal Can you provide a place where I can find these kind of questions? Maybe Chebyshev Integral Questions?
Upvote·0· Reply ·2014-06-24 20:11:04Aditya Agrawal And how do you write your answers in this kind of form?
man111 singh Using Online Latex Editor... Many Question Give in Preparation Books and Coaching Meterials.. Like Integration of 1/(1+x^4)^(1/4) or 1/(1-x^4)^(1/4) or (x)^(-1/2){(3+x^(1/3))^2} or (x)^(-1/2){(2+3x^(1/3))^(-2)} or x^(1/3).{1+x^(4/3)}^(1/7) or (x)^(-6){(1+2x^(3))^(2/3)}
x2 - 1 + 1/ (x2 -1)(x2+1)
seprate the terms of that x2 - 1 cancels
Then 1-x4 canbe written as (x+1)(x-1)(x2+1)
use partial fractions then
It would be very diffciults to solve if there was x4+1 ...Manish sir please suggest a method to solve x4+1
You can try this also
\int \frac{x}{\sqrt{x^{2}-1/x^{2}}}=\int \frac{x+1/x^{3}-1/x^{3}}{\sqrt{x^{2}-1/x^{2}}}
Aditya Agrawal Sir Then?